Improvement in methods of cleaning glass-molds



UNIT D STATE-S PATENT OFFICE.

WILLIAM A. O. IVUTH, OF PITTSBUBG, PENNSYLVANIA, ASSIGNOR TO HIIVL SELFWASHINGTON BECK AND HENRY FEUBHAKE, OF SAME PLACE.

IMPROVEMENT IN METHODS OF CLEANING GLASS-MOLDS.

Specification forming part of Letters Patent No. 221,138 dated October28, 1879 application filed October 2, 1879. i

To all whom it may concern:

Be it known that I, W. A. OTTO WUTH, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new known ofremoving it is by scouring the-mold.

with a stone dipped in oil or emery; but this is objectionable, becausealmost invariably the mold is made uneven thereby, is soon worn away,and the pattern, if any, is ruined by the rubbing off of the clear sharplines and corners. It is only by preserving these clear sharp lines' andcorners that it is possible to obtain pressed glassware resembling cutglassware.

In addition to this it is an operation which, owing to the hardness ofthe oxide, requires much time and labor, and is consequently a largeitem of expense, as the molds and plungers have to be cleaned every day.An on dinary plain mold will take from one to two hours to clean.

There are many molds of fine andintricate pattern which are nevercleaned, because it cannot be done without injuring or ruining them. a

By my invention I can remove the coating of magnetic oxide from the moldor plunger, andrcstore it to its first finish in a short time, withoutdestroying, injuring, or changing itsoriginal surface or pattern; and itconsists in treating the mold or plunger to a bath of melted borax,phosphate, or silicate of soda, or similar salt, which, uniting withoxide, separates it from the metallic iron, and forms therewith a glass,leaving the mold or plunger in a clean condition.

To enable others skilled in the art to use my invention, I will nowdescribe its use and operation.

I melt a sufficien't quantity of borax, phos phate, or silicate of soda,or other equivalent salt, in a suitable kettle to form a bath, in whichto immerse themold or plunger which is to be cleaned. The borax uniteswith the magnetic oxide, destroys its cohesion to the mold, and forms acolored glass. The mold is then taken out of the bath, and will be foundto be coated with a film or enamel of glass, which, when the moldbecomes cold, may be easily removed by slight blows of a suitablehammer, wooden mallet, or other instrument, as it is very brittle, or byimmersing it in.

boiling water.

It is necessary, in order to prevent the mold from becoming reoxidized,to permit it to cool, either as described or by remaining in the bathuntil. the bath becomes cold, before it is exposed to the air, as theaction of the air upon it while heated causes its reoxidation.

After the removal of the glassy film adhering to the mold when it istaken out of the bath, it will be found to be entirely free from thecoating of magnetic oxide, with, its finish unimpaired, and in conditionfor imme diate use.

The same bath may be used many times, its properties not being impairedby use. Its

quantity, however, will be gradually diminished, and it must thereforebe replenished from time to time.

Themolds and plungers may be placed in the'bath immediately after beingused, and while still hot from such use. The cost of the bath will bevery small. The salt will not attack or injure the metallic iron of themold.

By this means I am enabled'to effect the perfect removal from molds andplungers of the coating of magnetic oxide without labor and withoutinjury to the pattern or surfaces 1 thereof, and at very small expense.

What I claim as my invention, and desire to secure by Letters Patent,is-

The Wltllll1-dQSCPib6d method of cleaning In testimony whereof I, thesaid W. A. glass molds and plungers, consisting of sub- OTTO WUTH, havehereunto set my hand. initting them to a bath of melted borax phos- 7phate, or silicate of soda, or other salt, VhlCh, WILLIAM AUGUST OTTOWUTH' uniting with the coating of magnetic oxide Witnesses: of iron onthe molds and plnngers, will form JNo. K. SMITH,

a glass therewith, substantially as described. T. B. KERR.

